A detonating cord overlap transmission device

Abstract

The application provides a detonating cord lap joint transmission device, and relates to the technical field of oil and gas well completion, which comprises a positioning seat, an eccentric pipe arranged on the top working surface of the positioning seat, and a connecting pipe in communication with the eccentric pipe; the positioning seat is used for connecting with the tail disc of the upper jet perforating gun and fixing the upper section detonating cord of the upper jet perforating gun; the bottom end of the eccentric pipe is provided with positioning screws on both sides, and a coaxial center blind hole and an eccentric through hole are arranged in the eccentric pipe; the center blind hole is used for accommodating the end of the upper section detonating cord; the eccentric through hole is used for penetrating the lower section detonating cord; the upper end working surface of the connecting pipe is inserted into the lower end of the eccentric pipe, and is fixed through the positioning screws; the lower end working surface of the connecting pipe is provided with external threads; the application can be used without changing the size of the original perforating gun carrier upright pipe interface and the original intermediate joint, the use of the transmission pipe is completely cancelled, and the safety of the perforating operation is improved.

Description

Technical Field

[0001] This invention relates to the field of oil and gas well completion technology, and in particular to a detonating cord splicing and detonation transmission device. Background Technology

[0002] In oil and gas field development, perforation is essential after drilling and cementing to allow formation fluids to enter the wellbore. Perforation is a crucial process where a perforating gun string loaded with perforating cartridges is lowered to a predetermined formation in the well. A detonating device then detonates the detonating cord, which in turn detonates the perforating cartridges. The high-speed metal jet generated by the cartridges penetrates the casing, cement sheath, and formation, establishing a fluid channel between the formation and the wellbore. The quality of perforation directly impacts the productivity and ultimate recovery rate of oil and gas wells, and the reliability of the detonation transmission from the perforating gun string is the core factor determining the success or failure of the perforation operation.

[0003] In the existing technology, the detonating cord between adjacent perforating guns generally adopts the head-to-head detonation method, that is, a detonation tube is respectively fastened to the lower end of the detonating cord of the upper perforating gun and the upper end of the detonating cord of the lower perforating gun, and the end faces of the two detonation tubes are opposite each other. The detonation is achieved by the transmission of the detonation wave between the detonation tubes. While this detonation method can meet the needs of perforation operations to some extent, it has the following serious drawbacks: First, the detonator is a pyrotechnic hazardous material, mainly composed of high-energy explosives such as tantalum and RDX, which are highly sensitive and prone to accidental detonation due to collisions, friction, static electricity, and other factors during transportation, storage, and field use. Second, perforation operations are costly. For large-scale oil and gas field development, a single block may require perforation operations on hundreds of wells, with the cumulative cost of the detonator alone reaching hundreds of thousands of yuan. Furthermore, as a pyrotechnic material, the procurement, transportation, storage, and disposal of the detonator require significant investment of manpower, material resources, and financial resources, further increasing the overall cost of perforation operations. Third, on-site clamping of the detonator requires professional pyrotechnic operation qualifications and specialized clamping tools. The detonating cord end needs to be carefully processed before clamping, making the construction process cumbersome, inefficient, and severely impacting construction efficiency and extending the operation cycle. Summary of the Invention

[0004] The purpose of this invention is to provide a detonating cord splicing and detonation transmission device to solve the technical problems existing in the prior art.

[0005] To achieve the above-mentioned objectives, the technical solution adopted by this invention is as follows:

[0006] A detonating cord splicing and detonation device includes: a positioning seat, an eccentric tube disposed on the working surface of the top of the positioning seat, and a connecting pipe communicating with the eccentric tube; the positioning seat is used to connect with the tail plate of the magazine of the upper section of the firing gun and to fix the upper section of the detonating cord of the upper section of the firing gun; the bottom end of the eccentric tube is provided with positioning screws on both sides, and has a coaxial central blind hole and an eccentric through hole inside, the central blind hole is used to accommodate the end of the upper section of the detonating cord; the eccentric through hole is used to insert the lower section of the detonating cord; the upper working surface of the connecting pipe is inserted into the lower end of the eccentric tube and fixed by the positioning screws, and its lower working surface is provided with an external thread, the external thread matching the internal thread of the upper plate of the magazine of the lower section of the firing gun, and has a central through hole for the lower section of the detonating cord to pass through.

[0007] Furthermore, the positioning seat is provided with a screen tube, which is inserted into the positioning seat and fixed by the set screw. The upper section of the detonating cord is inserted into the screen tube and tightened by the set screw.

[0008] Furthermore, the screen tube has multiple holes arranged radially; the outer diameter of the screen tube is adapted to the inner diameter of the through hole on the lower working surface of the positioning seat.

[0009] Furthermore, the upper end of the positioning seat has an external thread, which matches the internal thread of the upper section firing port bullet rack tail plate. It has a stepped through hole in the center for the upper section detonating cord to pass through, and the large diameter section has a radial thread, which is threaded to the set screw.

[0010] Furthermore, the positioning seat is in the shape of a cylindrical step.

[0011] Furthermore, the outer diameter of the eccentric tube is smaller than the inner diameter of the intermediate joint of the perforating gun; the diameters of the central blind hole and the eccentric through hole are both larger than the upper section of the detonating cord.

[0012] Furthermore, the eccentric tube is cylindrical and made of polytetrafluoroethylene.

[0013] Furthermore, the working surface at one end of the eccentric tube is funnel-shaped.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] (i) This invention can be used normally without changing the original perforation gun cartridge holder straightening tube interface size or the original intermediate joint size, completely eliminating the use of the detonation tube, fundamentally eliminating all safety risks of the detonation tube in the process of procurement, transportation, storage, on-site crimping and downhole operation, including accidental detonation, premature detonation, delayed detonation and mis-detonation, and improving the safety of perforation operation.

[0016] (ii) Each perforating gun of the present invention can save multiple detonating tubes, reducing the cost per well; in addition, it also saves the costs of purchasing, transporting, storing and managing the disposal of detonating tubes, as well as the costs of special tools and labor required for crimping detonating tubes. The long-term economic benefits are very significant.

[0017] (III) This invention does not require on-site clamping of the detonating tube or fine processing of the detonating cord ends. It only requires threading the upper and lower detonating cords into the corresponding components and tightening the screws. The operation is simple and can be completed by ordinary construction personnel after simple training, which shortens the construction cycle and improves construction efficiency. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the internal structure of a detonating cord splicing and detonation transmission device disclosed in this invention;

[0019] Figure 2 This is a front view of the positioning seat of a detonating cord splicing and detonation transmission device disclosed in this invention;

[0020] Figure 3 This is a top view of the positioning seat of a detonating cord splicing detonation device disclosed in this invention;

[0021] Figure 4 This is a schematic diagram of the screen tube of a detonating cord overlapping detonation transmission device disclosed in this invention;

[0022] Figure 5 This is a front view of the screen tube of a detonating cord splicing detonation device disclosed in this invention;

[0023] Figure 6 This is a schematic diagram of the internal structure of the eccentric tube of a detonating cord splicing detonation device disclosed in this invention;

[0024] Figure 7 This is a top view of the eccentric tube of a detonating cord splicing detonation device disclosed in this invention;

[0025] Figure 8 This is a schematic diagram of the internal structure of the connecting pipe of a detonating cord splicing detonation device disclosed in this invention.

[0026] In the diagram: 1. Positioning seat; 2. Set screw; 3. Screen tube; 4. Eccentric tube; 5. Positioning screw; 6. Connecting pipe; 7. Upper detonating cord; 8. Intermediate joint; 9. Perforating gun; 10. Lower detonating cord. Detailed Implementation

[0027] To make the content of this invention easier to understand, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Identical components are represented by the same reference numerals. It should be noted that the terms "front," "rear," "left," "right," "up," and "down" used in the following description refer to directions in the accompanying drawings, while the terms "inner" and "outer" refer to directions toward or away from the geometric center of a specific component, respectively.

[0028] like Figure 1-8As shown, this embodiment provides a detonating cord splicing and detonation device, including: a positioning seat 1, an eccentric tube 4 located on the working surface of the top of the positioning seat 1, and a connecting pipe 6 communicating with the eccentric tube 4; the upper end of the positioning seat 1 has an external thread, which matches the internal thread of the upper section firing gun 9 cartridge rack tail plate, allowing direct connection without modifying the existing cartridge rack structure; its center has a stepped through hole for the upper section detonating cord 7 to pass through, the upper end hole diameter is 5.8mm and the depth is 45mm; the large diameter section of the positioning seat 1 has radial threads, which are threaded to the set screw 2, the set screw 2 has a blackened surface and is screwed in... In the radial threaded hole of the positioning seat 1, its conical end can press against the outer wall of the screen tube, and at the same time, it passes through the small round hole on the side wall of the screen tube 3 and presses against the outer wall of the detonating cord, thereby achieving double fixation of the screen tube 3 and the detonating cord, effectively preventing the perforating gun 9 in the detonating cord from moving due to vibration during the lowering process; all edges of the positioning seat 1 have preset chamfers to prevent scratching the detonating cord and other components; the positioning seat 1 is cylindrical and stepped, and the surface is blackened to improve rust resistance; the positioning seat 1 is used to connect with the tail plate of the perforating gun 9 in the previous section and fix the upper section of the detonating cord 7 of the perforating gun 9 in the previous section; the eccentric tube 4 is cylindrical and made of polytetrafluoroethylene. Made of polytetrafluoroethylene (PTFE), the eccentric tube 4 possesses excellent heat resistance, insulation, and machinability. Its soft texture prevents sharp edges from scratching the detonating cord, ensuring the eccentric tube 4 provides good sealing and restraint. This concentrates the detonation wave and products within the eccentric tube 4, preventing their diffusion and guaranteeing sufficient energy to detonate the lower section of detonating cord 10. The eccentric tube 4 has a total length of 114 mm and an outer diameter of 55 mm, allowing it to be inserted into the intermediate joint 8. One end of the eccentric tube 4 has a funnel-shaped working surface with a large diameter of 18 mm at the funnel opening, guiding the screen tube 3 smoothly into the eccentric tube 4 and preventing damage from sharp edges. Assembly errors cause the screen tube 3 to bend or be damaged; the eccentric tube 4 has positioning screws 5 on both sides of its bottom end, and has a coaxial central blind hole and an eccentric through hole inside. The central blind hole is used to accommodate the end of the upper section of detonating cord 7; the eccentric through hole is used to insert the lower section of detonating cord 10. The setting of the central blind hole and the eccentric through hole can ensure the reliability of the lateral transmission of the detonation wave; the outer diameter of the eccentric tube 4 is smaller than the inner diameter of the intermediate joint 8 of the perforating gun 9; the diameters of the central blind hole and the eccentric through hole are both larger than the upper section of detonating cord 7, so they will not protrude from the outer wall of the eccentric tube 4, avoiding friction and collision with the inner wall of the intermediate joint 8; the connecting pipe 6 is made of 45 Made of steel with a blackened surface, its upper working surface is inserted into the lower end of the eccentric tube 4 and fixed by the positioning screw 5 to ensure that the eccentric tube 4 can be smoothly fitted onto the connecting pipe 6 and the connection is firm; the lower working surface of the connecting pipe 6 is provided with an external thread, which matches the internal thread of the upper plate of the lower section firing gun 9, and a through hole is provided in the center for the lower section detonating cord 10 to pass through.

[0029] like Figure 1-4 As shown, furthermore, the positioning seat 1 is provided with a screen tube 3, which is a cylindrical structure made of H59 brass. In use, the screen tube 3 is inserted into the positioning seat 1 and fixed by the set screw 2. The upper section of the detonating cord 7 is inserted into the screen tube 3 and tightened by the set screw 2. The insertion depth into the positioning seat 1 is 24mm, and the length exposed at the lower end face of the positioning seat 1 is 70.5mm. This ensures that the upper and lower detonating cords have sufficient overlap length and avoids the screen tube 3 from being too long and colliding with the bottom of the eccentric tube 4. The screen tube 3 has multiple holes arranged radially. The outer diameter of the screen tube 3 is adapted to the inner diameter of the through hole on the lower working surface of the positioning seat 1. The above structure allows the screen tube 3 to break rapidly under the impact of the detonation wave. The detonation wave and detonation products can diffuse in all directions through the small round holes and the gaps after breakage, realizing lateral detonation.

[0030] Working principle: After the perforating gun string 9 is lowered to the predetermined formation in the well, the detonating cord of the upper perforating gun 9 is detonated by the detonation device. The high temperature and high pressure detonation wave and detonation products generated by the detonation of the detonating cord propagate downwards along the detonating cord. When it reaches the end of the detonating cord inside the screen tube 3, the detonation wave and detonation products impact the inner wall of the screen tube 3. Since the screen tube 3 has multiple small round holes distributed radially, and the brass screen tube 3 is instantly shattered into small fragments under the strong impact of the detonation wave, the detonation wave and detonation products diffuse outwards through the small round holes and the gaps after the fragmentation. Furthermore, since the upper and lower detonating cords are parallel and overlapped within the eccentric tube 4, and the PTFE eccentric tube 4 confines the detonation wave and detonation products within a limited space, the detonation wave can be transmitted laterally to the lower detonating cord with sufficient energy, detonating the lower detonating cord 10. After the lower detonating cord 10 is detonated, the detonation wave continues to propagate downwards, detonating the perforating projectile in the lower perforating gun 9. Simultaneously, the detonating cord of the next perforating gun is detonated through the next detonating cord overlap detonation transmission device, thereby achieving the sequential detonation of the entire perforating gun string 9, thus completing the perforation operation.

[0031] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A detonating cord splicing and detonation transmission device, characterized in that: include: Positioning seat (1), eccentric tube (4) disposed on the top working surface of the positioning seat (1), and connecting pipe (6) connected to the eccentric tube (4). The positioning seat (1) is used to connect with the tail plate of the cartridge of the upper section firing gun (9) and to fix the upper section detonating cord (7) of the upper section firing gun (9). The eccentric tube (4) has positioning screws (5) on both sides of its bottom end, and has a coaxial central blind hole and an eccentric through hole inside. The central blind hole is used to accommodate the end of the upper detonating cord (7); the eccentric through hole is used to insert the lower detonating cord (10). The upper working surface of the connector (6) is inserted into the lower end of the eccentric tube (4) and fixed by the positioning screw (5). The lower working surface is provided with an external thread, which matches the internal thread of the upper plate of the cartridge holder of the lower section perforating gun (9), and a through hole is provided in the center for the lower section detonating cord (10) to pass through.

2. The detonating cord splicing and detonation device according to claim 1, characterized in that: The positioning seat (1) is provided with a screen tube (3), the screen tube (3) is inserted into the positioning seat (1) and fixed by the set screw (2), the upper section detonating cord (7) is inserted into the screen tube (3) and tightened by the set screw (2).

3. The detonating cord splicing and detonation device according to claim 2, characterized in that: The screen tube (3) has multiple holes arranged radially; the outer diameter of the screen tube (3) is adapted to the inner diameter of the through hole on the lower working surface of the positioning seat (1).

4. The detonating cord splicing and detonation device according to claim 1, characterized in that: The upper end of the positioning seat (1) has an external thread, which matches the internal thread of the tail plate of the upper section firing gun (9). The center of the external thread has a stepped through hole for passing through the upper section detonating cord (7), and the large diameter section has a radial thread. The thread is threaded to the set screw (2).

5. The detonating cord splicing and detonation device according to claim 1, characterized in that: The positioning seat (1) is cylindrical and stepped.

6. The detonating cord splicing and detonation transmission device according to claim 1, characterized in that: The outer diameter of the eccentric tube (4) is smaller than the inner diameter of the intermediate joint (8) of the perforating gun (9); the diameters of the central blind hole and the eccentric through hole are both larger than the upper detonating cord (7).

7. The detonating cord splicing and detonation device according to claim 6, characterized in that: The eccentric tube (4) is cylindrical and made of polytetrafluoroethylene.

8. The detonating cord splicing and detonation device according to claim 7, characterized in that: The working surface of one end of the eccentric tube (4) is trumpet-shaped.

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